I might play something like that, depending on how it turns out and what its features are. After all, my favorite part of playing Grand Theft Auto is just exploring. And I like sim-like games where you are in control and there are a lot of possibilities. Also, this game might really help people with lucid dreaming. Any time I play video games during the day I will dream about them at night. So if the goal of the game is "lucidity" or if the game encourages lucid exploration and contemplation, that could really set people up for the real thing.
I recommend getting the book The Lean Startup by Eric Reis. The book is literally about how to effectively and efficiently create, test, and market new video games and apps. It sounds like you're off to a good start, though!